What is easy way to make a single node cluster barebone ( tasktracker )

I am experimenting one idea. Given smart configuration of Hadoop by Mapr, what would be easiest way to decommission a single node cluster and reincarnate to single seperate bare metal node to run just tasks?

Assume you have M3 vmware image. That is up and running. As first step, I stopped warden and zookeeper on the single node cluster. I removed only line in mapr-clusters.conf file. It is blank. Now, I restarted zookeeper and warden. Ideally, Mapr should be able to start the node with file services,web services, cldb etc. without joining any cluster.

As you see, services do not startup if you blanked mapr-clusters.conf file. I know there is complex way of decommissioning a node. I want a very simple way. What that would be? Why clearing config file should not work?